The invention relates to a method for increasing the flexibility of air conditioning systems that employ humidity removal.
Conventional air conditioning systems comprise three basic components which function in unison to provide cooling. These three system components include the compressor, the condenser, and the evaporator. With reference to FIG. 1, there is illustrated an air conditioning system 10 known in the art. The air conditioning system 10 moves a working fluid, or refrigerant, via a continuous closed network 23 through these operational components in a continuous cycle of operation. The refrigerant is typically composed of Freon but may consist of any fluid, such as alcohol or the like, capable of accepting and giving up heat energy as its temperature increases and decreases and as its state changes between a gas and a liquid.
Refrigerant enters the compressor 11 as a low pressure and temperature gas and is compressed. After compression, the refrigerant leaves the compressor 11 as a high temperature and pressure gas.
The refrigerant moves in its gaseous state to the condenser 13. At the condenser 13, the received refrigerant gas decreases in energy at a constant pressure and becomes totally subcooled as it leaves the condenser. Thereafter, the liquid refrigerant proceeds to the evaporator 17.
At the evaporator 17, the refrigerant pressure is reduced by expansion device 16. In the evaporator, energy is picked up from the air stream and the refrigerant leaves in a gaseous state. At the evaporator 17, the air to be cooled is, for example, initially at about 80 degrees Fahrenheit. Such air is moved by a fan through the evaporator 17 and becomes cooled to about 50 to 55 degrees Fahrenheit or lower.
Often times when the air requires greater dehumidification, heat exchanger 15 is provided to further subcool the refrigerant. The air passing over evaporator 17 exhibits more in latent and sensible cooling with the heat exchanger energized. However, the energy removed from the refrigerant by heat exchanger 15 is returned to the air stream after the air leaves evaporator 17. Thus, with heat exchanger 15 energized, the air leaving is at a higher dry bulb temperature (less sensible) and is low moisture centered (more latent), than with heat exchanger 15 unenergized.